Polyamide-imides

ABSTRACT

A series of polyamide-imides which are both tractable and soluble in polar solvents as well as stable at high temperatures has been prepared by the condensation polymerization of aromatic diamines or oligomers containing oxygen, sulfone, and optionally alkylidene linkages with trimellitic acid, trimellitic acid anhydride or trimellitic anhydride acid chloride.

United States Patent Brode et a1.

POLYAMlDE-IMIDES inventors: George Lewis Brode, Somerville;

James Hajime Kawakami, Piscataway, both of NJ.

Union Carbide Corporation, New York, NY.

Filed: Apr. 1, 1974 Appl. No.: 456,805

Related U.S. Application Data Division of Ser. No. 182,526, Sept. 21, 1971, Pat. No. 3,817,921, which is a continuation-in-part of Ser. No. 50,968, June 29, 1970, abandoned.

Assignee:

U.S. Cl. 260/571; ll7/l6l P; 260/570 R Int. Cl. C07c 93/06 Field Of Search 260/571 1 1 July 29, 1975 [56] References Cited UNITED STATES PATENTS 3,251,881 5/1966 Susi et a1. 260/571 X 3,514,415 5/1970 Karol 260/571 X 3,609,190 9/1971 Kuhlman 260/571 X Primary Examiner-Paul F Shaver Attorney, Agent, or FirmB. F. Crowe 5 7] ABSTRACT 4 Claims, No Drawings 3,897,497 1 2 POLYAMIDE-IMIDES where R is alkylidene o s This is a division of Ser. No. l82.526 filed Sept. 21, 1971, now US. Pat. No. 3,817,921, which is in turn a continuation-in-part of Ser. No. 50,968 filed June 29, 5 --C 1970, now abandoned.

BACKGROUND OF THE INVENTION and the like.

This invention relates to novel aromatic diamines and As so often happens in custom making high polymers more particularly to aromatic polyamide-imides synto improve a particular property, the desired end is thesized therefrom by condensation polymerization achieved only by the loss of one or more of the other with trimellitic acid anhydride or trimellitic anhydride properties. Thus for example, the substitution of amide.

acid chloride or trimellitic acid. linkages for imide linkages in polymers made from sim- The need for high polymeric coating materials which ple aromatic diamines improves tractability but renders exhibit good high temperature stability has been parthe polymer less thermally and oxidatively stable, (J. l. tially satisfied by the synthesis of aromatic polyimides Jones 6t stry and Industry, 1686, Sept. 22, by the condensation polymerization of arylene di- 1962). The polymers of this invention overcome the amines with aromatic dianhydrides. For example, difficulties associated with polyimides and at the same polyimides prepared in one instance from phenylenetime are useful in a wider range of applications than diamine and pyromellitic dianhydride having repeating a be Considered for any previously available high units are presented by the formula temperature polymer.

have been recommended for use as wire coatings. SUMMARY OF THE lNVENTlON While Such compounds fulfill the f high It has now been found that novel high temperature temperature Stability, t y were fleficlem other resistant, normally solid, polyamide-imides which have propertles Such as adhesion, elongation, @356 Of 'y flg, excellent physical and chemical properties can be synsolubility in organic solvents, and tractability or flow at thesized having repeating units represented by the forapplication temperature. Some of these difficulties mula:

O 0 ll l-l D N were overcome by either changing the imide linkages wherein D is a residue remaining after removal of both to amide linkages or to amide-imide "linkages or by reamine groups from at least one diamine having the formula:

\ /NRZ I l V H I 0 A Z /t 0 placing the arylene moiety of the diamine with polynuwherein A is a divalent radical selected from the group clear entities such as: consisting of:*

Z is a divalent radical selected from the group consist- DESCRIPTION OF THE INVENTION i f These novel polyamide-imides can be prepared by and wherein: 45 first condensing a trimellitoyl halide such as trimellitic m and p are integers having values of 0 to 4 anhydride acid chloride and one of the diamines de- I is an integer having values ofO to 5 with the proviso scribed above in a polar solvent such as dimethylacthat m and I cannot both be 0 at the same time etamide to form a low molecular weight polyamic acid E is a halogen including F. Clv or Br 50 which upon treatment with an equivalent amount of an each a is an integer having values of 0 to 4 HC'l scavengensuch as, anhydrous triethylamine rap- Ar is a divalent radical selected from the group conidly increases in'molec-ular weight to that of a high sisting of polymer. This reaction is illustrated below with trimeland R R is an alkylidene radical having 1 to 1() carbon 65 litoyl chloride and a sulfone ether diamine. The poatoms therein, and ly'amic acid is then dehydrated in'situ with a chemical I dehydrating agent such as acetic anhydride to the n is a rational number having values of 0 to about 25. polyamide-imide 11 hown below:

dimethylacetamide triethylamine Acetic Acid wherein x is a number representing the degree of polymerization, and is sufficiently large so as to afford a normally solid high molecular weight polymer.

The temperature at which the diamine-trimellitic an hydride acid chloride reaction takes place to form the polyamic acid is preferably about to +60C. with about 0 to +20C being particularly preferred.

The chemical conversion of polyamic acid to polyamide-imide which can be described as an imidization or dehydration step can be carried out in the temperature range of about l0 to 120C. with a range of about 20 to C. being preferred. Thermal imidization is also possible with and without the use of an azeotropic solvent to assist in the removal of water. Thermal imidization can be accomplished in the temperature range of about 4()0C., with a range of lO0-250C. being preferred.

Chemical dehydrating agents which can be used for the conversion of the polyamic acids to polyamideimides include but are not limited to aliphatic acid anhydrides, such as, acetic acid anhydride, propionic acid anhydride and the like; halogenated materials such as POCl SOCI and the like; molecular sieves, silica gel, phosphorous pentoxide, aluminum oxide and the like.

In the preparation of the polyamide-imides, pressure is not critical although it is preferred for economic reasons to employ atmospheric pressure. If desired however, subatmospheric as well as superatmospheric pressure can be used.

acetic anhydride x In preparing the polyamide-imides of this invention from trimellitic anhydride acid chloride it is preferred to use a specific order of addition as regards to the use of the HCl scavenging reagent. If the scavenger is added prior to the addition of trimellitoyl chloride the result is a lower molecular weight polyamide-imide. If the addition of the scavenger is delayed until after the polymerization reaction is substantially complete the result is a very slow polymerization rate because the solvent such as dimethylacetamide only partially complexes the hydrogen chloride formed during the polymerization process. lt has been unexpectedly found that if the scavenger is added soon after the addition of the trimellitoyl chloride one gets the best results as manifested by the production of a high molecular weight polyamide-imide with relatively fast polymerization rates.

Suitable scavenging agents for the removal of hydrogen chloride include tertiary amines containing aliphatic substituents such as trimethylamine, triethylamine, tripropylamine, tributylamine, and the like. Other reagents which can be used include cyclic organic bases, such as, pyridine, lutidine, collidine, quinoline, and the like, inorganic bases such as alkali metal hydroxides, alkali metal carbonates, alkali metal acetates, alkaline earth oxide, alkaline earth hydroxides, alkaline earth carbonates, alkali earth acetates, and the like; and organic oxides such as ethylene oxide, propylene oxide, and the like.

The polar solvents, used for the preparation of the instant polyamide-imides are those having a solubility parameter, 5, of about 9.8 to 15 as defined by H. Burrell, Official Digest, pages 725-758, October 1955. Exemplary solvents include N,N-dialkyl carboxylic acid amides where the alkyls are lower alkyls, such as, dimethyl acetamide, dimethylformamide and the like, heterocycles, such as N-methylpyrrolidone, tetrahydrothiophene-l, l-dioxide, and the like; organic sulfur oxides, such as, dimethyl sulfoxide, dimethyl sulfone, and the like; cyclic lactones such as 'y-butyrolactone, and the like; and mixtures of the above enumerated solvents with liquid hydrocarbons having about 5 to 20 carbon atoms, such as, toluene, xylene, and ketone such as methylethyl ketone, cyclohexanone and the like.

Although the polyamide-imides can be recovered by stripping off the solvent system following the polymerization and imidization steps, it is preferred to employ a precipitation technique using a solvent or solvents which are miscible with the reaction mixture solvents but in which the polyamide-imides themselves are insoluble. Suitable precipitating solvents include aliphatic ketones, such as, acetone, methyl ethyl ketone, diethyl ketone, and the like; aliphatic alcohols such as methanol, ethanol, isopropanol, and the like; aliphatic esters such as methyl acetate, ethyl acetate, butyl acetate and the like; and water, hydrocarbons such as benzene, toluene.

Thermoplastic polyamide-imide can be conveniently recovered by vacuum stripping the solution by processing through a vented extruder.

The precipitation recovery method facilitates filtration of the polyamides-imides and their purification by washing on the filter. Drying the polyamide-imides at temperatures of up to about 200C. effects removal of residual solvents in general.

An alternate preparation of these polyamide-imides consists in the direct condensation of the diamines with trimellitic acid anhydride instead of with the acid chloride followed by thermal dehydration or dehydration with an azeotropic solvent using a catalyst such as boric acid to produce a high molecular weight polyamideimide. This series of reactions is delineated below:

HO O \l/ C Q o o o 0 g H 0 00 00 HO C Gab-- 0 000B where .r is as defined previously.

Another alternate method of preparing those polyamide-imides consists in the condensation of the diamines described above with trimellitic acid in a manner similar to that described for the reaction with trimellitic acid anhydride above.

ln these two alternate methods, where dehydration or imidization is effected thermally, a temperature range of about 100 to 300C. can be used with a range of about 190 to 240C. being preferred.

Another facet of this invention resides in the method of preparation of the above-described novel diamines by the condensation of the sodium salt of p- 30 aminophenol: l with an equivalent amount of pdichlorodiphenyl sulfone alone in one instance; (2) with an equimolar quantity of both p-dichlorodiphenyl sulfone and bisphenol-A[2,2-bis(p-hydroxyphenyl)- propane], plus a further amount of p-dichlorodiphenyl sulfone equivalent to the amount of the sodium salt of p-aminophenol used; and (3) with an equimolar quan- 25 tity of both p-dichlorodiphenyl sulfone and hydroquinone plus an amount of p-dichlorodiphenyl sulfone equivalent to the amount of the sodium salt of paminophenol used.

These reactions are delineated in the equations below:

933 zn n 00m limo-G? on:

o hw o -oo CH V m wherein m is a rational number having average product distribution values ranging from about I to about 25.

mac-@115 $10 0 wherein m is as defined above. The success of these syntheses was unexpected sinc the literature indicated that p-aminophenol decomposed very rapidly in the presence of small amounts of oxygen and that aniline ionizes to the extent of with sodium hydroxide in anhydrous dimethyl sulfoxide bridge, for example in the reaction of p-nitro sodium phenolate and dichlorodiphenol sulfone followed by hydrogenation, the fldichlorodiphenyl sulfone contains traces of sulfides and other sulfur-containing poisons, because of the methody'of preparation of the sulfone, which destroy common hydrogenation catalysts required for the hydrogenation step. This sequence of reactions is delineated in the equation below:

Hydi'ogenat ion Catalyst (cf. 0. Dolman et al, Can. J. Chem., 45,911, 1967 and R. Konaka et al, J. Am. Chem. Soc., 90, I801, l968). It was therefore surprising that the pure diamines could be obtained by this approach.

The more common or conventional technique for preparing aromatic diamines which involves the reaction of nitrophenol with a chloronitrobenzene to afford the corresponding dinitro compound whose nitro groups are subsequently reduced to amine groups is not as amenable to a commercial process becase first of all it involves an extra reaction step. Secondly, in the specific preparation of a diamine containing a sulfone Because of the unique combination of physical and chemical properties exhibited by the polyamide-imides of this invention,zand particularly the unusual combination of tractability and high temperature stability they a t a G with trimellitoyl chloride and on the other hand a dicontains an extra bisphenol-A unit the polyamideamine oligomer disclosed in Bclgizm Pat. No. 71 1,729 imidfr 0f the present invention having the formula having the formula 9 o oo z II 9' o o 2 00.

converted to a polyamide-imide with trimellitoyl chlo- Contains an extra diphenyl Sulfonc unit- It Should be ride. Whereasaspeculative, unknown polyamide-imide 45 'l that Pal 711,729 teflches p p'f derived from the latter prior art diamine having the forof polylmldes y not a Preparatlon P y m imides. This difference in molecular architecture af- 0 n 2 CH3 9 0 CH II I fords polyamide-imides made by the practice of this invention superior to those made from the diamines in the recited patent in the oxygen index flammability test (described in J. Fire & Flammability Vol. 1, pg. 36, 1970), thermal stability, solvent resistance and in having higher glass transition and heat distortion temperatures.

It should be borne in mind that some of the commerto the completely imidized form. On conversion to the completely imidized form, they become thermosetiresins through crosslinking. This intelligence is dispensed in, for example, US. Pat. No. 3,428,486 issued to N. J. George on Feb. 18, 1969 as assignor to the P. D. George Company. In contrast the polyamide-imides of the claimed invention are not post-cured and are not crosslinked, that is, they are thermoplastic resins in the classical sense and are used as such without conversion to another form such as a thermoset resin; Unlike these prior art resins the claimed polyamide-imide can be softened and reworked by heating to elevated temperatures.

The methods described supra for the synthesis of the diamines used in the preparation of the polyamideimides of this invention are equally applicable to the preparation of monoamines as well as higher polyamines. The novel amines thus made available may be delineated by the formula:

Wherein G is a radical selected from the group consistcially available polyamide-imides extant are useful as 30 g of:

(a is) coatings, laminates, adhesives, insulation and the like. only when converted through a post-curing operation Wherein L is a radical selected from the group consisting of:

gig?

(Yl J j i )l when m wherein Y is a radical having the formula:

m, v. and a are integers having values of 0 to 4, r, b and fare integers having values of 0 to 2 with, the proviso that the sum of a plus, r, b or f 3, k is an integer having values of 0 to l,

T is selected from the group consisting of hydrogen,

Cl or a valence bond with the proviso that T is hydrogen or Cl when k=0 and T is a valence bond when k=1.

E is a halogen selected from the group consisting of F, C1 or Br,

5 is a rational number having values of about 1 to about 25. and

Ar is a divalent radical selected from the group consisting of and EXAMPLE 1 Preparation of 4,4'-[ sulfonylbis(p-phenyleneoxy )ldianiline A 500 ml. round bottom, 3-necked flask fitted with a magnetic stirring bar, thermometer, additional funnel, and nitrogen inlet tube was charged with 21.82 grams (0.20 moles) of p-aminophenol and 100 ml. of oxygen free dimethyl sulfoxide. The resultant solution was stirred under nitrogen and then 15.93 grams of 50.22 per cent aqueous sodium hydroxide was added dropwise to the addition funnel. The contents of the funnel were mixed, rinsed with l ml. of oxygen free water into the reaction mixture. About minutes was required for this addition period during which time the temperature rose from about 26 to 38C. A Dean- Stark water trap and reflux condenser was attached to the reaction flask. The reaction mixture was heated to 160 over a two hour period while 150 ml. of chlorohenzene was added in portions to the reaction flask.

Water was azeotroped from thereaction mixture until the chlorobenzene collected in the Dean-Stark trap was free of water. The reaction mixture was cooled to 135C. and 28.72 grams (0.10 moles) of dichlorodiphenyl sulfone dissolved in 40 ml. of hot chlorobenzene was added rapidly to the reaction mixture. An exothermic reaction resulted increasing the reaction mixture temperature from 135 to 150C. After stirring for an additional 45 minutes the temperature had increased to 160C. The reaction mixture was maintained at a temperature of 160 for 3 hours after which it was allowed to cool overnight to room temperature. The cooled reaction mixture was poured into 500 ml. of water precipitating crude 4,4-[sulfonylbis(4- phenyleneoxy)]dianiline as a solid. This material was filtered, dissolved in tetrahydrofuran, dried over magnesium sulfate and the solvent removed'under vacuum to afford a yield of 87 per cent amounting to 37.6 grams having a melting point of l77-l 87C. Recrystallization of 0.21 grams of this product in 1 ml. of hot tetrahydrofuran and 1 ml. of isopropanol afforded a 0.15 gram per cent) yield of the product having amelting point of 188-l9lC. Analysis by mass spectrograph showed a parent peak of 432 which matches the formula:

The identity of the 4,4'-[sulfonylbis(pphenyleneoxy)]dianiline produced was further demonstrated by elemental analysis data shown below:

Calculated (7zl Found (71) Preparation of Oligomer Diamine from p-Aminophenol, bisphenol A and p-Dichlorodiphenyl Sulfone Into a 12 liter flask was charged 716.5 grams (3.14 moles) of bisphenol A, 687.5 grams (6.38 moles) paminophenol, 4.2 liters of dimethyl sulfoxide and 2.5 liters of toluene. After purging with nitrogen, 1003.8 grams (12.62 moles) of a 50.2% solution of sodium hydroxide was added and the pot temperature brought to l 10-120C. The water was removed from the toluene azeotrope using a Barrett tube, after which the toluene was distilled off until the pot temperature reached 160C. At this point, the reaction mixture was cooled to C. and 1807.5 grams (6.28 moles) of dichlorodiphenyl sulfone added as a solid. The pot was reheated to 160C. for one hour and then cooled. At C. a solution of sodium p-aminophenolate, prepared by dehydrating a mixture of 10.9 grams (0.] mole) paminophenol, 8.0 grams (0.1 mole) of a 50% sodium hydroxide solution, 30 ml. of dimethyl sulfoxide and 20 ml of toluene, was added.

After cooling to room temperature, the solution was filtered to remove sodium chloride and coagulated in ablender from 2% sodium hydroxide solution containing 1% sodium sulfite. The precipitated diamine was washed with a hot 1% solution of sodium sulfite and methanol and dried in a vacuum oven at 80C.

The yield of diamine was 2655 grams (96.5%) and the equivalent weight was 456 grams.

This oligomer diamine has the formula shown below:

wherein n has an average value of about 1. EXAMPLE 4 EXAMPLE 3 Preparation of Polyamide-imides v A three liter, three necked round bottom flask Preparation of ollgomer diamlne from p-ammophenol. 1

h dm uinone and dichlorodi he '1 sulfone 15 equipped with a mechanical stirrer, thermometer and y q p p i nitrogen inlet tube was charged with 173.00 grams (0.4 A 500 ml.. 4-neCk6d flask fitt d with a th m r. mole) of recrystallized sulfone ether diamine prepared Dean Stark moisture trap and reflux condenser.-nitro-. as in Example 1 .and having a melting point of gen inlet tube, mechanical stirrer. and addition funnel 191 192C d 900 1 f anhydrous di h l as ged with 11x01 mole) f hydroquinonet 20 etamide freshly distilledover molecular sieves. This regrams moles) of P P' P Y action mixture was cooled at l0C. with a dry ice acetone, 1091 grams 1 mole) of pp tone bath and 84.22 grams (0.4 mole) of distilled mgramS (0108 mole) Of anhydrous Potassium Carbonate mellitoyl chloride was added in portions at such a rate and 75 ml. of chlorobenzene. Nitrogen was bubbled as to keep the temperature between -l0 and -C. through the reaction mixture for 30 minutesand l l0 5 This operation took approximately minutes during ml. Of freshly distilled and deoxygenated sulfolane (tetwhich time the reaction mixture appeared to increase rahydrothiophene-l,l-dioxid as added dropwise t0 in the viscosity. After maintaining the temperature for the stirred mixture. The reaction mixture was heatedto 1 hour at 0C., 60 ml. of anhydrous triethylamine was 140C. with an oil bath. The reaction mixture was then added dropwise at a rate sufficient to keep the tempercooled to 25C. and had a light grey color and a consis- 3O ature below about +5C. Reaction was allowed to contency of a slurry. After about 40 minutes thereaction tinue with stirring for about 10 minutes during which mixture was raised to about 183C. at which time about time a noticeable increase in viscosity resulted. After 20 ml. of a water-chlorobenzene mixture was collected minutes the reaction mixture was extremely viscous.

in the trap. The reaction mixture was then raised to a An additional 300 ml of dimethylacetamide was added temperature of about 200 C. over a period of 30 minand the mixture stirred at 15C. for a total of 3 hours utes at which time about 7 ml. of water-chlorobenzene timed from the addition of the trimethylamine. Then had distilled over into the trap. After 15 minutes at 100 ml of pyridine and 200 ml of acetic anhydride was 210C. chlorobenzene was added dropwise (75 ml.) to added and the mixture was stirred overnight (approxiassist the azeotroping reaction removing the reaction rnately 12 hours) at room temperature. The product moving the last traces of water. The reaction tempera- 40 was coagulated in water (the volume of water being ture was kept at 210C. for an additional 1.5 hours after about 10 times'that of the reaction mixture), slurried which it was allowed to cool overnight under nitrogen in acetone and dried in a vacuum oven at 200C. A to room temperature. The next morning a light purple yield of 234 grams 100 per cent) of a polyamide-imide solid remained which partially dissolved in .200 ml. of having repeating units represented by the formula bedimethylformamide. This mixture was filtered to relow:

IMEQFQQWQ t move sodium chloride and gave a total yield of about where x is as defined'previously was obtained as a light 89 per cent of the hydroquinone-oligomer-sulfone yellow solid having reduced viscosity in dimethylacether diamine having the formula shown below: etamide at 25C. when measured as a 0.2 per cent solu- H N aE J Q S J ONHZ- 1 The product was coagulated in isopropanol washed tion of 0.97. Sample plaques for physical testing were with water again with isopropanol. The melting point prepared by compression molding at 350C. There was was 222-229C. 7 no change in reduced viscosity as a result of the compression molding operation. Films of this polyamideimide were also prepared by solvent castings from dimethylacetamide. The mechanical properties of both the molded plaques and the cast films are shown in Table 1 below:

TABLE I Sulfone ether polyamide-imide mechanical properties Environmental stress aging characteristics were determined as follows.

A calculated stress (in psi) was applied to a 1-30 mil thick polymer film approximately /a inch wide and 4 inches long by means of an lnstron Tensile Tester. The film was wrapped with an adsorbent cloth and a solvent was applied (to the fllm and cloth). The time was then noted and again noted when rupture occurs or 10 minutes without rupture achieved. if rupture has not occurred, the film was examined for craze marks and tested for brittleness by the ASTM D 256-56 Pendulum Impact Strength Method. The results of the solvent stress crack resistance evaluation in 3 solvents is shown in Table 11 below:

Preparation of Polyamide-lmide from Sulfone Ether Diamine and Trimellitic Acid Anhydride To a 100 ml flame dried flask with a mechanical stir rer, Dean Stark trap, nitrogen inlet, and thermometer was added 60 ml N-methylpyrrolidinone and 21.63 grams (0.05 mole) 4,4-bis[oxyphenyleneamineldiphenyl sulfone. The reaction mixture was heated to 45C. and approximately one-third of 9.61 grams trimellitic acid anhydride was added. This portion dissolved in 20 minutes. and a 2nd portion was added at 48C. The

cos o o o \C a final portion was added 20 minutes later. in 35 minutes all the acid anhydride dissolved and reacted at the anhydride functional group. About 25 ml of chlorobenzene was added and the reaction mixtures heated to 160 in 1 hour. The first drops of water came over at this time. About 1 hour later 5 ml fresh chlorobenzene was added at 172C. This procedure was repeated 10 minutes later. About 40 minutes later the temperature was 21 1C. and no water was present. Then 0.6 gram of boric acid dried at 160C. (vacuum) was added. After stirring for 20 hours at 210, the reaction mixture was diluted with N-methylpyrrolidinone and coagulated in acetone. The reduced viscosity in dimethylacetamide was 0.41.

EXAMPLE 6 Preparation of Polyamide-lmide from Sulfone Ether Diamine oligomer and Trimellitic Acid Anhydride To a 250 ml flame dried flask fitted with a mechanical stirrer, thermometer, nitrogen inlet, and Dean Stark trap was added one-halfof21.63 grams (0.05 mole) 4,- 4'-[oxypheny1eneamine]diphenyl sulfone and ml sulfolane. The reaction mixture was vacuum degassed,

and then heated to 49. Then about one-third of 9.61 grams (0.05 mole) trimellitic acid anhydride was added. When this portion dissolved, a 2nd portion was added. In a total of 1 hour, all the trimellitic acid anhydride was dissolved. Then ml of chlorobenzene was added and the mixture heated to in 30 minutes. The first drop of water was removed at 134 (clear solution). At one hour later, a precipitate resulted. About 60 m1 chlorobenzene and -8 ml water had distilled. At this time 0.6 gram boric acid, the 2nd half of the diamine, and 100 ml dry ortho-dichlorobenzene were added. Then the mixture was heated to 178 in 1 hour, and to 205 in an additional hour. Most of the solid was now in solution. About five hours later, the temperature was 215, and 17 m1 of solvent had distilled over with traces of water. Eleven hours later the temperature was 230C. The reaction mixture was fairly viscous. The reaction mixture was coagulated in isopropanol, slurried in acetone, and dried for 16 hours at 200C. to yield 28 grams of a yellow powder. The reduced viscosity in dimethylacetamide at 25C. was 0.81. The mechanical properties were identical to the polyamide-imides prepared from trimellitoyl chloride.

CONTROL A Example 4 was repeated with the exception that 0.4 mole of pyromellitic dianhydride was used in placeof trimellitoyl chloride and the dehydration of the amic acids to imides was effected thermally at 300C. instead of with a chemical dehydrating agent. The resultant polymide having repeating units represented by the formula shown below:

where x is as defined previously, was intractable. An attempt to compression mold this polyimide at 400C. resulted in decomposition.

EXAMPLE 7 Preparation of Oligomer Diamine from p-Aminophenol, Bis-phenol A and p-Dichlorodiphenyl sulfone.

grams of chlorine terminated polysulfone oligomer having the formula shown below:

0.133 mole of sodium p-aminophenolate was condensed with a product prepared from 0.133 mole of sodium biphenolate A and 0.20 mole of dichlorodiphenyl sulfone. Titration of the resulting amine in a perchloric acid-glacial acetic acid mixture (0.01 molar) indicated an equivalent weight of 828.2.

EXAMPLE 9 Example 7 was repeated with the exception that 0.10 mole of sodium p-aminophenolate, was condensed with 0.15 mole of sodium bisphenolate A and 0.20 mole of dichlorodiphenyl sulfone. Titration of the diamine obtained showed an equivalent weight of 1,069.

EXAMPLE 10 A 4-necked one liter flask equipped with a mechaniwhere the average value of n=1 and a molecular weight of 729.24 added. The temperature was further increased to 140C. over a period of 1 hour and minutes and held at this temperature for 4 hours. The con' tents of the flask was then coagulated in 1500 ml. of water producing an oil. The oil was dissolved in chloroform and the chloroform layer washed with water until the water layer was only lightly colored. This took five 500 ml additions of water. The reddish brown solution was evaporated to 200 m1 and the residue coagulated in 2000 ml of isopropanol. A solid white precipitate resulted which was collected by vacuum filtration and washed 3 times with 200 m1 portions of isopropanol. After drying in a vacuum overnight :1 yield of 17.1 grams of diamine was obtained having the formula shown below:

cal stirrer, thermometer, nitrogen inlet tube and Dean Stark water trap was charged with l 14.88 grams (0.40 mole) of dichlorodiphenyl sulfone, 45.62 grams (0.20 mole) of bisphenol A, and 200 m1 of dimethyl sulfoxide. Solution was vacuum degassed and 15.836 grams (0.20 mole) of 50.52% aqueous sodium hydroxide solution added at room temperature. The mixture was heated at C. for 15 minutes and 400 m1 of degassed chlorobenzene was added. Stirring was continued for 2 hours at -140C. until no further water collected in a water trap. The chlorobenzene was removed by heating the mixture to C. and distilling. The mixture was maintained at 160C. for an additional 4 hours. There was then added 33.65 grams (0.40 mole) of recrystallized p-aminophenol, 46.60 grams (0.60 mole) of 50.52% of aqueous sodium hydroxide solution The nuclear magnetic resonance spectrum in trifluoroacetic acid indicated an aromatic to methyl ratio of 4.5 plus or minus 0.2. The n. m. r. of the same solution two days later gave a ratio of 4.6 plus or minus 0.1.

EXAMPLE 8 Example 7 was repeated with the exception that n an average oi 1 and 300 ml of deoxygenated chlorobenzene. The mixture was heated for 2.5 hours to remove water and heating continued at 160165C. for 2 hours. The mixture was filtered free of salt and the filtrate coagulated in isopropanol yielding 146.5 grams (84%) of diamine having an equivalent weight of 509.9. This diamine had the formula below:

9 HzlLz where has an average value of 1.33.

EXAMPLE 1] A 4-necked one liter flask equipped with a mechanical stirrer. thermometer. nitrogen inlet tube and Dean Stark water trap was charged with 28.72 grams (0.1 mole) of dichlorodiphenyl sulfone. 45.62 grams (0.2 mole) of bisphenol A. 21.82 grams (0.2 mole) of paminophenol in 200 ml of dimethyl sulfoxide and 100 ml of toluene. The solution was vacuum degassed and 47.51 grams (0.6 mole) of 50.52% aqueous sodium hydroxide solution added. The mixture was heated to remove water at which point the reaction mixture had a temperature of 124C. Then 57.4 grams (0.2 mole) of dichlorodiphenyl sulfone was added. Toluene was distilled off raising the pot temperature to 140C. at which temperature the reaction mixture was kept overnight. Coagulation of the mixture is isopropanol yielded 912 grams of diamine which by titration had an equivalent weight of 1 127.8 and had the formula shown below:

wherein y has an average value of about 4.

EXAMPLE 12 A 12 liter flask equipped with a mechanical stirrer, thermometer, condenser, gas inlet tube and an addition funnel was charged with 716.5 grams (3.14 moles) of GJQ 431 03 0 0? L CH 0 bisphenol A, 687.5 grams (6.38 moles) of paminophenol, 4.2 liters of dimethyl sulfoxide and 2.5 liters of toluene. After purging with nitrogen, 1003.8 grams (12.62 moles) of a 50.2% aqueous solution of sodium hydroxide was added and pot temperature raised to l l0l 20C. Water was removed as a toluene azeotrope and the remaining toluene distilled off by raising the pot temperature until it reached 160C. At this point the reaction mixture was cooled at 110C. and 1807.5 grams (6.28 moles) of para-paradichlorodiphenyl sulfone added as a solid. The reaction flask was reheated to 160C. for 1 hour and then cooled to 150C. at which point a solution of sodium paminophenolate, prepared by dehydrating a mixture of 10.9 grams (0.1 mole) of p-aminophenol, 8.0 grams (0.1 mole) of a aqueous sodium hydroxide solution, 30 ml of dimethyl sulfoxide and 20 m1 of toluene, was added.

The reaction mixture was cooled to room temperature, the solution filtered to remove sodium chloride and coagulated in a blender from 2% sodium hydroxide aqueous solution containing 1% sodium sulfite. The

50 precipitated diamine was washed with a hot 1% aqueofiogjo o ous solution of sodium sulfite and methanol and dried in a vacuum oven at C.

The yield of diamine which had the formula shown below:

n Wt. 7: of Fraction 21.1 1 39.4 2 22.0 3. 4 and above 17.5

This distribution is typical of linear condensation reactions.

EXAMPLE 13 Using the procedure described in Example 4 for the Then, 723 g. (2.52 moles) of dichlorodiphenyl sulfone was added to the flask and the pot temperature maintained at 160-165C. for one hour with stirring. At this point a mixture of 11.2 g. (0.105 moles) of paminophenol, 35 ml of dimethyl sulfoxide, ml. of toluene and 8.0 g. of 50.2% aqueous sodium hydroxide solution, which had been previously treated to remove water by the procedure described above in the first paragraph of the instant examples was added and mixture stirred for 1 hour at l40155C. The product oligomer diamine was recovered by pouring the reaction mixture into an excess of water containing 2% sodium hydroxide and 1% sodium sulfite with stirring, filtering, washing on the filter with water and drying. A yield of oligomer diamine of 929 g. (84.5%) was obtained having an equivalent weight of 474 (theoretical 437) as determined by amine -end group" titration with an perchloric acid-acetic acid mixtuge deseribed above which corresponds to a molecular weight of 948.

The formula of thisv oligomer diamine is io o o o n v Y 7' CH3 q '1 so o v weight polyamide-imide having a reduced viscosity of EXAMPLE 14 Preparation of 4,4-bis(p-oxyphenyleneamine)diphenyl sulfone A 5-liter 4-necked flask equipped with a mechanical stirrer, nitrogen inlet tube, thermometer, addition funnel, and Dean Stark water trap was charged with 1000 ml. of dimethyl sulfoxide and degassed under a vacuum of 63 mm. of mercury for 25 minutes at 250C. Then 458 grams (4.2 moles) of crude practical grade paminophenol was added. The reaction mixture was warmed to 58C. with nitrogen sparging and 2000 ml. of toluene and 574.4 grams (2.0 moles) of dichlorodiphenyl sulfone was added. The mixture was heated to 145C. for 3.5 hours. The product 4,4-bis(oxyphenyleneamine)diphenyl sulfone had an equivalent weight of 218.7:02.

EXAMPLE 15 Preparation of Oligomer Diamine A 5 liter, 3-necked flask equipped with a mechanical stirrer, thermometer, condenser, Barrett tube and hi trogen inlet tube was charged with 286.6 g. (1x257 moles) of bisphenol A, 275.0 g. (2.52 moles) of paminophenol, 1.7 liters of dimethyl sulfoxide, 1.0 liter of toluene and 40.15 g. (5.034 moles) of a 50.21% aqueous solution of sodium hydroxide. The mixture was heated to reflux under nitrogen until all of the water was removed as a toluene-water azeotrope.

wherein has an average value of 1.2.

EXAMPLE 16 Preparation of Oligomer Diamine EXAMPLE 17 Preparation of Polyamide-lmide from Oligomer Diamine A 5 liter round bottom flask equipped with a mechanical stirrer, thermometer, condenser, gas inlet tube and addition funnel was charged with 746 g. (0.785 moles) of the oligomer diamine prepared in Example 16 in 3 liters of, dimethylacetamide under argon together with 1659 (0.785 moles) of trimellitoyl chloride. The resulting solution was stirred for 0.5 hours at 10C., and then (0.785 moles) of triethylamine added to the mixture in order to scavenge the HCl generated. The polymerw'hich formed was in an amic acid form, that is, containing both amide and carboxyl groups in its backbone. This was converted to an amide-imide polymer by the addition of 79.4 g. (0.785 moles) of acetic anhydride and stirring the reaction mixture overnight. The polyamide-imide was recovered from solution by coagulatin from an excess of water followed by filtration, water washing and drying.

The resultant polyamide-imide had repeating units represented by formula:

wherein n has an average value of about 1. This polymer had a reduced viscosity measured as a 0.2% solution in dimethylacetamide at 25C. was 0.50 and could be extruded through a vented extruder and ram injection molded. Plaques of this polymer obtained by compression molding at 1500 psi. and 350C. showed the following physical properties:

T,, 215C. T 245C. Flow Temperature 320C.

Tensile Strength (ASTM D638-56) 12,200 psi.

Tensile Modulus (ASTM D638-56) 279,000 psi.

Elongation at break (ASTM D63856) 12% Pendulum impact Strength 120 ft. lbs/in.

(ASTM D-256-56) EXAMPLE 18 Preparation of Polyamide-lmide Using the procedure described in Example 17 with the Oligomer diamine prepared in Example 16 having a molecular weight of 890, a solid polyamide-imide was prepared having the repeating units represented by the formula:

{na s wherein x is as defined previously. This polymer was processed in a single vent, single screw extruder at a stock temperature of 3l0340C. Clear, gel-free strands with good appearance were extruded. Production rates of over 1000 grams/hour were achieved using a 24/1 L/D one inch screw. The reduced viscosity of the polymer increased slightly from 0.50 to 0.56. during the extrusion process indicating that no degradation occurs. After processing this polymer showed a melt flow range of psi.

EXAMPLE 19 Preparation of Polyamide-lmide from ether sulfone Oligomer diamine and trimellitoyl chloride One mole of the ether sulfone oligorner diamine prepared in Example 16 from one mole of sodium bisphenolate A, 2 moles of sodium p-aminophenalate and 2 moles of dichlorodiphenylsulfone having an average molecular weight of 910 was charged to a 5 liter resin flask with one mole of trimellitoyl chloride in 3 liters of dimethylacetamide. After stirring the mixture for one hour under an inert atmosphere at ambient temperatures, 1.l moles of triethylamine was added and stirring continued for 2 hours. The very viscous solution of polyamic acid which formed was converted to the corresponding amide-imide by the addition of one mole of acetic anhydride. The polymer was coagulated from the reaction mixture in water with stirring and dried in vacuum. A 96% yield of polyamidc imide having a reduced viscosity in dimethyl acetimide at 25C. of 0.60

'was' obtained having the following repeating units:

W3 Mo ogo T ca. 220C. Tensile Modulus 288,000 psi. Tensile Strength 10,700 psi. Yield 7.07: Elongation at break 1071 Pendulum impact strength 146 ft. lb/in. Dielectric Strength mil plaque) 1,168 volts/mil.

Volume Resistivity 5.8 X 10" ohm-cm. Dielectric constant 3.9

60 cps. l Kc 3.9 Dissipation Factor 0.0054

60 cps. l Kc 0.0045

Environmental stress aging characteristics Trichloroethylene 1,000 psi; 10 min; noncrazed. nombrittle,

Xylene crazed, non-brittle.

Ethyl acetate crazed. non-brittle.

1.000 psi; 10 min; non- 2,000 psi; 10 min; non- EXAMPLE 20 Preparation of Polyamide-lmide from 4,4'-bis(p-oxyphenyleneamine)diphenyl sulfone and Trimellitoyl chloride was added. The viscosity of the reaction mixture in creased significantly and triethylamine hydrochloride precipitated. 1 Hour later 10 ml. of acetic anhydride and 10 ml. of pyridine were added and the mixture stirred overnight at room temperature. After filtration of the reaction mixture the polyamide imide wascoagulated in an excess of acetone, filtered and dried at 100 overnight in vacuum. The yield of polyamide-imide having repeating units represented by the formula below:

0 ec p 1 wherein x is as defined previously, was 47.9 grams and the reduced viscosity was 0.50.

Melt flow determinations were made by weighing in grams the amount of polyamide-imide which at a temperature of 350C. and under a pressure of 44 psi. flowed through an orifice having a diameter of 0.0825 inches and a length of 0.315 inches over a 10 minute period. This value was recorded as MP A second set of melt flow measurements (MP was made by allowing the polyamide-imide to remain at a temperature of 350C. for 0.5 hours before running the melt flow test. The ratio of MP divided by MF is an indication of the thermal stability of the polymer, the ideal value being 1.0.

Melt index measurements were performed as described in ASTM D-1238-61.

Reduced viscosity was determined by weighing a 0.2 gm. sample of polyamide-imide into a ml. volumetric flask and adding dimethylacetamide thereto. After solution was complete, additional solvent was added to exactly the fiducial line while the flask was maintained in a 25C. constant temperature bath. The solution was thereafter filtered through a sintered glass funnel and the viscosity of a sample determined in a viscometer tube at 25C. Reduced viscosity values were computed by using the equation:

wherein:

1,, is the efflux time for the solvent t, is the efflux time for the polyamide-imide solution.

Tensile impact strengths were determined in conformity with ASTM D-256-56. Glass transition temperature (T also referred to as second order phase transition temperatures refer to the inflection temperature found by plotting the resilience, (recovery from 1% elongation) ofa film, ranging in thickness from 3 to 15 mils., against the temperature. A detailed explanation for determining resilience and inflection point is to be found in an article by A. Brown (Textile Research Journal) Vol. 25. 1955 at page 891.

T is the temperature at which the tensile modulus (measured in accordance with ASTM D-256-56) reaches 100 psi.

EXAMPLE 21 A polyphenylene ether amine was prepared as follows:

To a 2 liter, 4-neck flask equipped with a Dean Stark trap, condenser nitrogen inlet tube and thermometer was added 110.0 grams (1.008 mole) p-aminophenol and 500 ml. of toluene. The system was purged with nitrogen and 400 ml. of dimethylsulfoxide added. The system was purged again with nitrogen and 81.5 grams (1.05 mole) of 49.15% aqueous sodium hydroxide added. The solution was heated to l10-l2 C. and water removed via the toluene/water azeotrope. After complete dehydration (approximately 4-5 hours), toluene was removed until the pot temperature reached 135C.

A concentrated solution of Aroclor 5460 (274 grams) (0.5 mole) in 250 ml. of hot toluene was added via an addition funnel. The remaining toluene was then distilled off. The pot was heated to 160C. and maintained 1 hour before cooling to room temperature.

At room temperature, the reaction mixture was vacuum filtered to remove sodium chloride and coagulated. Coagulation was accomplished by pouring the filtrate slowly into distilled water (1 to of water) contained in a 3 liter blender and stirred at a high speed. Vacuum filtration through a fritted glass funnel afforded a dark colored diamine. The diamine was washed further with hot distilled water, then dried at 60C. under vacuum.

The dried amine (76% yield) was dark brown in color and had a titrated amine equivalent of 365. The chlorine content by elemental analysis was 36.2%. The mass spectrum indicated the product was composed of 9 amines:

IR 3 S( ti -I 2)3 EXAMPLE 22 To a 2 liter, 4-neck flask equipped with a Dean Stark trap, condenser, nitrogen inlet tube and thermometer was added 60.02 grams (0.55 mole) of p-aminophenol, 5708 grams (0.25 mole) of Bisphenol A and 500 ml. of toluene. The system was purged with nitrogen and 450 ml. of dimethylsulfoxide added. The system was purged again with nitrogen and 84.64 grams (1.04 mole) of 49.15% aqueous sodium hydroxide added.

The solution was heated to l l0-120C. and water removed via the toluene/water azeotrope. After complete dehydration (approximately 4-5 hours), toluene was removed until the pot temperature reached 135C.

A concentrated solution of Aroclor 5460 (274 grams).(0.5 mole) in 250 ml. of hot toluene was added via an addition funnel. The remaining toluene was then distilled off. The pot was heated to 160-l65."C. and maintained 2 hours, before cooling to room temperature.

At room temperature, the reaction mixture was vacuum filtered to remove sodium chloride and coagulated. Coagulation was accomplished by pouring the filtrate slowly into distilled water (1 to 10 of water) containing 2% sodium hydroxide (1%sodium sulfite) contained in a 3 liter blender and stirred at a high speed. Vacuum filtration through a fritted glass funnel afforded a light colored diamine. The diamine was washed further with a hot 1% sodium sulfite solution and ispropanol, then dried at C. under vacuum.

The dried diamine was tan in color and had a titrated amine equivalent of 696.

EXAMPLE 23 To a 2 liter, 4-neck flask equipped with a Dean Stark trap, condenser, nitrogen inlet tube and thermometer was added 121.1 grams (1.11 moles) p-aminophenol, 114.15 grams (0.5 mole) bisphenol A, 400 ml. toluene and 500 m1. dimethylsulfoxide. The solution was saturated with nitrogen and 171.32 grams (2.105 moles) of 49.15% aqueous sodium hydroxide added. The pot temperature was increased to ll0120C. and water removed via the toluene/water azeotrope. After com plete dehydration (approximately 4-5 hours), the remaining toluene was removed until the pot temperature reached 150-l60C.

The heating was discontinued and the reaction cooled to C. Solid dichlorodiphenylsulfone (258.3 grams, 0.9 moles) was added, followed by hexachlorobenzene 28.5 grams, 0.1 mole). After completing the addition of hexachlorobenzene, the pot was heated to l60l65C. and maintained 1 hour before cooling to room temperature.

At room temperature, the reaction mixture was vacuum filtered to remove sodium chloride and coagulated. Coagulation was accomplished by pouring the filtrate slowly into distilled water (1 to 10 of water) containing 2% sodium hydroxide/1% sodium sulfite contained in a 3 liter blender and stirred at a high speed. Vacuum filtration through a fritted glass funnel afforded a light colored diamine. The diamine was washed further with a hot 1% sodium sulfite solution and isopropanol, then dried at 85C. under vacuum.

The dried diamine was tan in color and had a titrated amine equivalent of 429.

EXAMPLE 24 To a 3 liter, 3-neck flask equipped with a Barrett tube, condenser, nitrogen inlet tube and thermometer was added 115.0 grams 1.05 mole) of p-aminophenol, 114 grams (0.5 mole) of Bisphenol A and 800 ml. of toluene. The system was purged with nitrogen and 800 ml. of dimethylsulfoxide added. The system was purged again with nitrogen and 164 grams (2.03 mole) of 49.15% aqueous sodium hydroxide added. The solution was heated to l05-l 20C. and water removed via the toluene/water azeotrope. After complete dehydration,

reached 135C.

A concentrated solution of Aroclor 1268 (453 grams, 1.0 mole) in 500 ml. of hot toluene was added via an addition funnel. The remaining toluene was then distilled off. The pot was heated to l60-175C. and maintained 2 hours, before cooling to room temperature.

At room temperature, the reaction mixture was vacuum filtered to remove sodium chloride and coagulated. Coagulation was accomplished by pouring the filtrate slowly into agitated water l/l ratio) containing 2% sodium hydroxide/1% sodium sulfite. Filtration afforded a light colored diamine. The diamine was washed further with a hot 1% sodium sulfite solution, then dried at 85C. under vacuum.

The dried diamine was ten in color and had a titrated amine equivalent of 650. The product melted in the range of 125-l60C.

EXAMPLE 25 1,3-bis(p-Oxyphenyleneamine )tetrachlorobenzene (Hexachlorobenzene etherdiamine) Into a 500 ml 4-necked flask equipped with stirrer, and a thermometer, and reflux condenser inlet was charged while under nitrogen, 200 ml toluene, 75 ml l60l6'5C. for 2 hours. Toluene was then distilled off until the internal temperature reached 172C.

After cooling to room temperature, the contents of the flask were filtered, washed with small amounts of dimethylsulfoxide, and coagulated from water. After washing to neutrality and drying, titration yielded amine equivalent of 256 (theory 215).

, EXAMPLE 27 Preparation of Oligomer Diamine from p-Aminophe'nol, bisphenol A, hexachlorobenzene and p-Dichlorodiphenyl Sulfone Into a 3 liter flask was charged 171.225 grams (0.75 moles) of bisphenol A,165.88 grams (1.52 moles) of p-aminophenol, 700ml. of dimethyl sulfoxide and 600 ml. of toluene. After purging with nitrogen, 244.96

. grams (3.01 moles) of 49.15% sodium hydroxide solu- DMSO and 21.83 grams (0.2 moles) of p-aminophenol.

After purging with nitrogen, 16.05 grams (0.20 moles) ofa 49.6% solution of sodium hydroxide was added and the pot temperature brought to l l C. The water was removed from the toluene azeotrope using a Barrett tube, after which the toluene was distilled off until the pot temperature reached 130C. At this point, 28.5 grams (0.1 mole) of hexachlorobenzene was added as a solution in 150 mi of toluene. The pot was heated to 160C. for 3.5 hours and then cooled.

At room temperature, the solution was filtered to remove sodium chloride and coagulated in a blender from 1% sodium hydroxide solution containing 1% sodium sulfite. The precipitated diamine was washed with a hot 1% solution of sodium sulfite and dried in a vacuum oven at C.

The yield of diamine was 36.2 grams (97%) and the equivalent weight was 228 grams.

This Oligomer diamine has the formula shown below:

1,3-bis(p-Oxyphenyleneamine)tetrachlorobenzene In a 500 ml 4-necked flask equipped with stirrer, thermometer, reflux condenser and nitrogen inlet were combined under nitrogen 100 ml toluene, 100 ml dimethylsulfoxide. 28.5 grams (.1 mole) hexachlorobenzene, 21.83 grams (.2 moles) p-aminophenol and 49.0 grams (.3 moles) K CO 1% H O). After azeotroping off the water, the internal temperature was increased to C. for one hour and then to tion was added and the pot temperature brought to l 10l20C. The water was removed from the toluene azeotrope using a Barrett tube, after which the toluene was distilled. off until the pot temperature reached 145C. At this point, 215.38 grams (0.75 moles) of dichlorodiphenyl was added as a solid. The pot was reheated to 160C. for one hour and then cooled to 110C. At 110C., a solution of 213.83 grams (0.75 moles) of hexachlorobenzene dissolved in 600 ml. of hot toluene was added. The pot was again heated to -160C. for one hour and finally cooled to room temperature.

At room temperature, the solution was filtered to remove sodium chloride and coagulated in a blender from 0.5% sodium hydroxide solution containing 0.5% sodium sulfite. The precipitated diamine was washed with a hot 1% solution of sodium sulfite and dried in a vacuum oven at 80C.

The yield of diamine was 291.8 grams (73.9%) and the equivalent weight was 452 grams.

EXAMPLE 28 Preparation of Polyamide-imides A 250 ml., three-neck round bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen inlet tube was charged with 16 grams (0.70 equiv.) of 1,3-bis(P-oxyphenyleneamine)tetraehlorobenzene) as in Example 25 and 48 ml. ofanhydrous dimethylacetamide. The reaction mixture was cooled to l0C. with an ice bath and 7.42 grams (0.0352 mole) of distilled trimellitoyl chloride was added at such a rate as to keep the temperature around 10C. After maintaining the temperature for one hour at 10C., 7.35 grams (.0726 mole) of anhydrous triethylamine was added dropwise at a rate sufficient to keep the temperature below 20C. Reaction was allowed to continue with stirring for about ten minutes during which time a noticeable increase in viscosity resulted. After thirty min- 37 utes the reaction mixture was extremely viscous. Then, 8 grams (.0784 moles) of acetic anhydride) was added and the mixture was stirred overnight at room temperature.

The product was coagulated in water (the volume of water being about ten times that of the reaction mixture), slurried in acetone and dried in a vacuum oven at 160C. A yield of 19.8 grams (96%) of a polyamideimide having repeating units represented by the formula below:

wherein X denotes the degree of polymerization and has a value high enough so as to denote a normally solid polymer. The polymer had a reduced viscosity 0.49 dl/gram when measured as a 0.2 percent solution in dimethylacetamide.

Sample plaques were prepared by compression molding at 350C. The glass transition temperature (Tg) of the polymer was 245C.

EXAMPLE 29 l.3-bis(p-Oxyphenyleneamine )tetrachlorobenzene Polyamide-imide A 250 ml. three-neck flask fitted with a mechanical the temperature stayed below l5C. After stirring at 0l0C. for one hour, 9.1 grams (0.09 moles) of triethylamine was added. After stirring for one hour further, the remaining 10.0 grams (0.044 equiv.) of 1,3- bis(p-Oxyphenyleneamine) tetrachlorobenzene was added in one portion. The viscosity of the reaction mixture increased significantly and another -l20 ml. of dimethylacetamide was required. Three hours later, 10 grams (.098 moles) of acetic anhydride was added and stirring continued overnight.

What is claimed is: 1. An amine having the formula:

I H NQ OW QNH stirrer, thermometer and nitrogen inlet tube was charged with 10.0 grams (0.044 equiv) of l,3-bis(p- Oxyphenyleneamine)tetrachlorobenzene and 60 ml. of distilled dimethylacetamide. The reaction mixture was cooled to 10C. and 9.28 grams (0.044 moles) of distilled trimellitoyl chloride was added at such a rate that wherein a is an integer having values of 6 to 8.

2. Amine claimed in claim I wherein a is 6. 3. Amine claimed in claim 1 wherein a is 7. 4. Amine claimed in claim 1 wherein a is 8. 

1. AN AMINE HAVING THE FORMULA:
 2. Amine claimed in claim 1 wherein a is
 6. 3. Amine claimed in claim 1 wherein a is
 7. 4. Amine claimed in claim 1 wherein a is
 8. 